reader.c

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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*                                                                           */
/*                  This file is part of the program and library             */
/*         SCIP --- Solving Constraint Integer Programs                      */
/*                                                                           */
/*  Copyright 2002-2022 Zuse Institute Berlin                                */
/*                                                                           */
/*  Licensed under the Apache License, Version 2.0 (the "License");          */
/*  you may not use this file except in compliance with the License.         */
/*  You may obtain a copy of the License at                                  */
/*                                                                           */
/*      http://www.apache.org/licenses/LICENSE-2.0                           */
/*                                                                           */
/*  Unless required by applicable law or agreed to in writing, software      */
/*  distributed under the License is distributed on an "AS IS" BASIS,        */
/*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
/*  See the License for the specific language governing permissions and      */
/*  limitations under the License.                                           */
/*                                                                           */
/*  You should have received a copy of the Apache-2.0 license                */
/*  along with SCIP; see the file LICENSE. If not visit scipopt.org.         */
/*                                                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/**@file   reader.c
 * @ingroup OTHER_CFILES
 * @brief  interface for input file readers
 * @author Tobias Achterberg
 */

/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/

#include <assert.h>
#include <string.h>
#if defined(_WIN32) || defined(_WIN64)
#else
#include <strings.h> /*lint --e{766}*/
#endif
#include <math.h>

#include "scip/def.h"
#include "blockmemshell/memory.h"
#include "scip/set.h"
#include "scip/clock.h"
#include "scip/pub_misc.h"
#include "scip/reader.h"
#include "scip/prob.h"
#include "scip/pub_var.h"
#include "scip/var.h"
#include "scip/pub_cons.h"
#include "scip/cons.h"
#include "scip/pub_message.h"

#include "scip/struct_reader.h"


/** copies the given reader to a new scip */
SCIP_RETCODE SCIPreaderCopyInclude(
   SCIP_READER*          reader,             /**< reader */
   SCIP_SET*             set                 /**< SCIP_SET of SCIP to copy to */
   )
{
   assert(reader != NULL);
   assert(set != NULL);
   assert(set->scip != NULL);

   if( reader->readercopy != NULL )
   {
      SCIPsetDebugMsg(set, "including reader %s in subscip %p\n", SCIPreaderGetName(reader), (void*)set->scip);
      SCIP_CALL( reader->readercopy(set->scip, reader) );
   }
   return SCIP_OKAY;
}

/** internal method to create a reader */
static
SCIP_RETCODE doReaderCreate(
   SCIP_READER**         reader,             /**< pointer to store reader */
   const char*           name,               /**< name of reader */
   const char*           desc,               /**< description of reader */
   const char*           extension,          /**< file extension that reader processes */
   SCIP_DECL_READERCOPY  ((*readercopy)),    /**< copy method of reader or NULL if you don't want to copy your plugin into sub-SCIPs */
   SCIP_DECL_READERFREE  ((*readerfree)),    /**< destructor of reader */
   SCIP_DECL_READERREAD  ((*readerread)),    /**< read method */
   SCIP_DECL_READERWRITE ((*readerwrite)),   /**< write method */
   SCIP_READERDATA*      readerdata          /**< reader data */
   )
{
   assert(reader != NULL);
   assert(name != NULL);
   assert(desc != NULL);
   assert(extension != NULL);

   SCIP_ALLOC( BMSallocMemory(reader) );
   BMSclearMemory(*reader);

   SCIP_ALLOC( BMSduplicateMemoryArray(&(*reader)->name, name, strlen(name)+1) );
   SCIP_ALLOC( BMSduplicateMemoryArray(&(*reader)->desc, desc, strlen(desc)+1) );
   SCIP_ALLOC( BMSduplicateMemoryArray(&(*reader)->extension, extension, strlen(extension)+1) );
   (*reader)->readercopy = readercopy;
   (*reader)->readerfree = readerfree;
   (*reader)->readerread = readerread;
   (*reader)->readerwrite = readerwrite;
   (*reader)->readerdata = readerdata;

   /* create reading clock */
   SCIP_CALL( SCIPclockCreate(&(*reader)->readingtime, SCIP_CLOCKTYPE_DEFAULT) );

   return SCIP_OKAY;
}

/** creates a reader */
SCIP_RETCODE SCIPreaderCreate(
   SCIP_READER**         reader,             /**< pointer to store reader */
   SCIP_SET*             set,                /**< global SCIP settings */
   const char*           name,               /**< name of reader */
   const char*           desc,               /**< description of reader */
   const char*           extension,          /**< file extension that reader processes */
   SCIP_DECL_READERCOPY  ((*readercopy)),    /**< copy method of reader or NULL if you don't want to copy your plugin into sub-SCIPs */
   SCIP_DECL_READERFREE  ((*readerfree)),    /**< destructor of reader */
   SCIP_DECL_READERREAD  ((*readerread)),    /**< read method */
   SCIP_DECL_READERWRITE ((*readerwrite)),   /**< write method */
   SCIP_READERDATA*      readerdata          /**< reader data */
   )
{
   assert(reader != NULL);
   assert(set != NULL);
   assert(name != NULL);
   assert(desc != NULL);
   assert(extension != NULL);

   SCIP_CALL_FINALLY( doReaderCreate(reader, name, desc, extension, readercopy, readerfree, readerread, readerwrite,
      readerdata), (void) SCIPreaderFree(reader, set) );

   return SCIP_OKAY;
}

/** frees memory of reader */
SCIP_RETCODE SCIPreaderFree(
   SCIP_READER**         reader,             /**< pointer to reader data structure */
   SCIP_SET*             set                 /**< global SCIP settings */
   )
{
   assert(reader != NULL);
   assert(set != NULL);

   if( *reader == NULL )
      return SCIP_OKAY;

   /* call destructor of reader */
   if( (*reader)->readerfree != NULL )
   {
      SCIP_CALL( (*reader)->readerfree(set->scip, *reader) );
   }

   BMSfreeMemoryArrayNull(&(*reader)->name);
   BMSfreeMemoryArrayNull(&(*reader)->desc);
   BMSfreeMemoryArrayNull(&(*reader)->extension);

   /* free clock */
   SCIPclockFree(&(*reader)->readingtime);

   BMSfreeMemory(reader);

   return SCIP_OKAY;
}

/** returns TRUE, if reader is responsible for files with the given extension */
static
SCIP_Bool readerIsApplicable(
   SCIP_READER*          reader,             /**< reader */
   const char*           extension           /**< extension of the input file name */
   )
{
   assert(reader != NULL);
   assert(reader->extension != NULL);

   return (extension != NULL && strcasecmp(reader->extension, extension) == 0)
      || (extension == NULL && *(reader->extension) == '\0');
}

/** reads problem data from file with given reader or returns SCIP_DIDNOTRUN */
SCIP_RETCODE SCIPreaderRead(
   SCIP_READER*          reader,             /**< reader */
   SCIP_SET*             set,                /**< global SCIP settings */
   const char*           filename,           /**< name of the input file */
   const char*           extension,          /**< extension of the input file name */
   SCIP_RESULT*          result              /**< pointer to store the result of the callback method */
   )
{
   SCIP_RETCODE retcode;

   assert(reader != NULL);
   assert(set != NULL);
   assert(filename != NULL);
   assert(result != NULL);

   /* check, if reader is applicable on the given file */
   if( readerIsApplicable(reader, extension) && reader->readerread != NULL )
   {
      SCIP_CLOCK* readingtime;

      /**@note we need temporary clock to measure the reading time correctly since in case of creating a new problem
       *       within the reader all clocks are reset (including the reader clocks); this resetting is necessary for
       *       example for those case we people solve several problems using the (same) interactive shell
       */

      assert(!SCIPclockIsRunning(reader->readingtime));

      /* create a temporary clock for measuring the reading time */
      SCIP_CALL( SCIPclockCreate(&readingtime, SCIP_CLOCKTYPE_DEFAULT) );

      /* start timing */
      SCIPclockStart(readingtime, set);

      /* call reader to read problem */
      retcode = reader->readerread(set->scip, reader, filename, result);

      /* stop timing */
      SCIPclockStop(readingtime, set);

      /* add time to reader reading clock */
      SCIPclockSetTime(reader->readingtime, SCIPclockGetTime(reader->readingtime) + SCIPclockGetTime(readingtime));

      /* free the temporary clock */
      SCIPclockFree(&readingtime);
   }
   else
   {
      *result = SCIP_DIDNOTRUN;
      retcode = SCIP_OKAY;
   }

   /* check for reader errors */
   if( retcode == SCIP_NOFILE || retcode == SCIP_READERROR )
      return retcode;

   /* check if the result code is valid in case no reader error occurred */
   assert( *result == SCIP_DIDNOTRUN || *result == SCIP_SUCCESS );

   SCIP_CALL( retcode );

   return SCIP_OKAY;
}


/* reset the variable name to the given one */
static
void resetVarname(
   SCIP_VAR*             var,                /**< variable */
   SCIP_SET*             set,                /**< global SCIP settings */
   const char*           name                /**< variable name */
   )
{
   const char * oldname;

   assert( var != NULL );
   assert( name != NULL );

   /* get pointer to temporary generic name and free the memory */
   oldname = SCIPvarGetName(var);
   SCIPsetFreeBufferArray(set, &oldname);

   /* reset name */
   SCIPvarSetNamePointer(var, name);
}


/** writes problem data to file with given reader or returns SCIP_DIDNOTRUN */
SCIP_RETCODE SCIPreaderWrite(
   SCIP_READER*          reader,             /**< reader */
   SCIP_PROB*            prob,               /**< problem data */
   SCIP_SET*             set,                /**< global SCIP settings */
   FILE*                 file,               /**< output file (or NULL for standard output) */
   const char*           extension,          /**< file format */
   SCIP_Bool             genericnames,       /**< using generic variable and constraint names? */
   SCIP_RESULT*          result              /**< pointer to store the result of the callback method */
   )
{
   SCIP_RETCODE retcode;

   assert(reader != NULL);
   assert(set != NULL);
   assert(set->buffer != NULL);
   assert(extension != NULL);
   assert(result != NULL);

   /* check, if reader is applicable on the given file */
   if( readerIsApplicable(reader, extension) && reader->readerwrite != NULL )
   {
      const char* consname;
      const char** varnames = NULL;
      const char** fixedvarnames = NULL;
      const char** consnames = NULL;
      SCIP_VAR** vars;
      SCIP_VAR** fixedvars;
      SCIP_CONS** conss;
      SCIP_CONS* cons;
      SCIP_Real objscale;
      char* name;
      int nfixedvars;
      int nconss;
      int nvars;
      int i;

      vars = prob->vars;
      nvars = prob->nvars;
      fixedvars = prob->fixedvars;
      nfixedvars = prob->nfixedvars;

      /* case of the transformed problem, we want to write currently valid problem */
      if( prob->transformed )
      {
         SCIP_CONSHDLR** conshdlrs;
         int nconshdlrs;

         conshdlrs = set->conshdlrs;
         nconshdlrs = set->nconshdlrs;

         /* collect number of constraints which have to be enforced; these are the constraints which currency (locally)
          * enabled; these also includes the local constraints
          */
         nconss = 0;
         for( i = 0; i < nconshdlrs; ++i )
         {
            /* check if all constraints of the constraint handler should be written */
            if( set->write_allconss )
               nconss += SCIPconshdlrGetNConss(conshdlrs[i]);
            else
               nconss += SCIPconshdlrGetNEnfoConss(conshdlrs[i]);
         }

         SCIPsetDebugMsg(set, "Writing %d constraints.\n", nconss);

         SCIP_CALL( SCIPsetAllocBufferArray(set, &conss, nconss) );

         /* copy the constraints */
         nconss = 0;
         for( i = 0; i < nconshdlrs; ++i )
         {
            SCIP_CONS** conshdlrconss;
            int nconshdlrconss;
            int c;

            /* check if all constraints of the constraint handler should be written */
            if( set->write_allconss )
            {
               conshdlrconss = SCIPconshdlrGetConss(conshdlrs[i]);
               nconshdlrconss = SCIPconshdlrGetNConss(conshdlrs[i]);
            }
            else
            {
               conshdlrconss = SCIPconshdlrGetEnfoConss(conshdlrs[i]);
               nconshdlrconss = SCIPconshdlrGetNEnfoConss(conshdlrs[i]);
            }

            SCIPsetDebugMsg(set, "Conshdlr <%s> has %d constraints to write from all in all %d constraints.\n", SCIPconshdlrGetName(conshdlrs[i]), nconshdlrconss, SCIPconshdlrGetNConss(conshdlrs[i]));

            for( c = 0; c < nconshdlrconss; ++c )
            {
               conss[nconss] = conshdlrconss[c];
               nconss++;
            }
         }
      }
      else
      {
         conss = prob->conss;
         nconss = prob->nconss;
      }

      if( genericnames )
      {
         SCIP_VAR* var;
         int size;

         /* save variable and constraint names and replace these names by generic names */

         /* allocate memory for saving the original variable and constraint names */
         SCIP_CALL( SCIPsetAllocBufferArray(set, &varnames, nvars) );
         SCIP_CALL( SCIPsetAllocBufferArray(set, &fixedvarnames, nfixedvars) );
         SCIP_CALL( SCIPsetAllocBufferArray(set, &consnames, nconss) );

         /* compute length of the generic variable names:
          * - nvars + 1 to avoid log of zero
          * - +3 (zero at end + 'x' + 1 because we round down)
          * Example: 10 -> need 4 chars ("x10\0") 
          */
         size = (int) log10(nvars+1.0) + 3;

         for( i = 0; i < nvars; ++i )
         {
            var = vars[i];
            varnames[i] = SCIPvarGetName(var);

            SCIP_CALL( SCIPsetAllocBufferArray(set, &name, size) );
            (void) SCIPsnprintf(name, size, "x%d", i + set->write_genoffset);
            SCIPvarSetNamePointer(var, name);
         }  

         /* compute length of the generic variable names */
         size = (int) log10(nfixedvars+1.0) + 3;

         for( i = 0; i < nfixedvars; ++i )
         {
            var = fixedvars[i];
            fixedvarnames[i] = SCIPvarGetName(var);

            SCIP_CALL( SCIPsetAllocBufferArray(set, &name, size) );
            (void) SCIPsnprintf(name, size, "y%d", i);
            SCIPvarSetNamePointer(var, name);
         }

         /* compute length of the generic constraint names */
         size = (int) log10(nconss+1.0) + 3;

         for( i = 0; i < nconss; ++i )
         {
            cons = conss[i];
            consnames[i] = SCIPconsGetName(cons);

            SCIP_CALL( SCIPsetAllocBufferArray(set, &name, size) );
            (void) SCIPsnprintf(name, size, "c%d", i);
            SCIPconsSetNamePointer(cons, name);
         }
      }

      /* adapt objective scale for transformed problem (for the original no change is necessary) */
      objscale = prob->objscale;
      if( prob->transformed && prob->objsense == SCIP_OBJSENSE_MAXIMIZE )
         objscale *= -1.0;

      /* call reader to write problem */
      retcode = reader->readerwrite(set->scip, reader, file, prob->name, prob->probdata, prob->transformed,
         prob->objsense, objscale, prob->objoffset,
         vars, nvars, prob->nbinvars, prob->nintvars, prob->nimplvars, prob->ncontvars,
         fixedvars, nfixedvars, prob->startnvars,
         conss, nconss, prob->maxnconss, prob->startnconss, genericnames, result);

      /* reset variable and constraint names to original names */
      if( genericnames )
      {  
         assert(varnames != NULL);
         assert(fixedvarnames != NULL);
         assert(consnames != NULL);
         for( i = nconss - 1; i >= 0; --i )
         {
            cons = conss[i];

            /* get pointer to temporary generic name and free the memory */
            consname = SCIPconsGetName(cons);
            SCIPsetFreeBufferArray(set, &consname);

            /* reset name */
            SCIPconsSetNamePointer(cons, consnames[i]);
         }

         for( i = nfixedvars - 1; i >= 0; --i )
            resetVarname(fixedvars[i], set, fixedvarnames[i]);

         for( i = nvars - 1; i >= 0; --i )
            resetVarname(vars[i], set, varnames[i]);

         /* free memory */
         SCIPsetFreeBufferArray(set, &consnames);
         SCIPsetFreeBufferArray(set, &fixedvarnames);
         SCIPsetFreeBufferArray(set, &varnames);
      }

      if( prob->transformed )
      {
         /* free memory */
         SCIPsetFreeBufferArray(set, &conss);
      }
   }
   else
   {
      *result = SCIP_DIDNOTRUN;
      retcode = SCIP_OKAY;
   }

   /* check for reader errors */
   if( retcode == SCIP_WRITEERROR )
      return retcode;

   SCIP_CALL( retcode );

   return SCIP_OKAY;
}

/** gets user data of reader */
SCIP_READERDATA* SCIPreaderGetData(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return reader->readerdata;
}

/** sets user data of reader; user has to free old data in advance! */
void SCIPreaderSetData(
   SCIP_READER*          reader,             /**< reader */
   SCIP_READERDATA*      readerdata          /**< new reader user data */
   )
{
   assert(reader != NULL);

   reader->readerdata = readerdata;
}

/** sets copy method of reader */
void SCIPreaderSetCopy(
   SCIP_READER*          reader,             /**< reader */
   SCIP_DECL_READERCOPY  ((*readercopy))     /**< copy method of reader or NULL if you don't want to copy your plugin into sub-SCIPs */
   )
{
   assert(reader != NULL);

   reader->readercopy = readercopy;
}

/** sets destructor of reader */
void SCIPreaderSetFree(
   SCIP_READER*          reader,             /**< reader */
   SCIP_DECL_READERFREE  ((*readerfree))     /**< destructor of reader */
   )
{
   assert(reader != NULL);

   reader->readerfree = readerfree;
}

/** sets read method of reader */
void SCIPreaderSetRead(
   SCIP_READER*          reader,             /**< reader */
   SCIP_DECL_READERREAD  ((*readerread))     /**< read method */
   )
{
   assert(reader != NULL);

   reader->readerread = readerread;
}

/** sets write method of reader */
void SCIPreaderSetWrite(
   SCIP_READER*          reader,             /**< reader */
   SCIP_DECL_READERWRITE ((*readerwrite))    /**< write method */
   )
{
   assert(reader != NULL);

   reader->readerwrite = readerwrite;
}

/** gets name of reader */
const char* SCIPreaderGetName(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return reader->name;
}

/** gets description of reader */
const char* SCIPreaderGetDesc(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return reader->desc;
}

/** gets file extension of reader */
const char* SCIPreaderGetExtension(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return reader->extension;
}

/** return whether the reader can read files */
SCIP_Bool SCIPreaderCanRead(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return (reader->readerread != NULL);
}

/** return whether the reader can write files */
SCIP_Bool SCIPreaderCanWrite(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return (reader->readerwrite != NULL);
}

/** gets time in seconds used in this reader for reading */
SCIP_Real SCIPreaderGetReadingTime(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   return SCIPclockGetTime(reader->readingtime);
}

/** enables or disables all clocks of \p reader, depending on the value of the flag */
void SCIPreaderEnableOrDisableClocks(
   SCIP_READER*          reader,             /**< the reader for which all clocks should be enabled or disabled */
   SCIP_Bool             enable              /**< should the clocks be enabled? */
   )
{
   assert(reader != NULL);

   SCIPclockEnableOrDisable(reader->readingtime, enable);
}

/** resets reading time of reader */
SCIP_RETCODE SCIPreaderResetReadingTime(
   SCIP_READER*          reader              /**< reader */
   )
{
   assert(reader != NULL);

   /* reset reading time/clock */
   SCIPclockReset(reader->readingtime);

   return SCIP_OKAY;
}